As someone that all that he knew about perspective was vanishing points exist and meet at the horison and that there can be 2 points and then its called 2 point pesepective it has teached me a lot of usefull things like:
-Avoiding warped perspective (i did not understand the method shown and i personally find the 60 degree cone of vision method eazier to understand
https://www.youtube.com/watch?v=RsbzCHLsQuQ)
-Changing eye level
-Placing figures (or anything that you want to be of a specific height relative to [INSERT THING HERE])
-Giving items different orientation (i think i got this from the problems on page 46 , I remember there was a problem where the author told the reader to stack a bunch of bricks togheer in different orientations and draw them using different VPs but i think thats a false memory because i cant find that part)
-Interiours
-Finding the center
-Spacing in pespective (the thing i hoped to find here , its
on page 113)
-dividing a surface (and drawing a checkerboard)
-Reflections (they use the same VPs as the object they are reflecting)
And other things i most likely forgot i picked up from here yet i did